Control device



I Feb. 1s, 1936.

L. w. EGGLESTON 2,031,408

'CONTROL DEVICE Filed Jan. 24, 1935 Y INVENTOR- 23 um ma f Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE ooN'rRoL DEVICE Application January 24, 1933, Serial No. 653,263

22 Claims.

My invention relates to new and useful improvements in control devices, and more particularly to a device which is responsive to moisture content of air or other gases.

An object of my invention is to provide a device which will respond readily to slight Variations in moisture content of air or other gases to actuate a switch element, for example.

Another object is to provide such a device particularly adapted for operation in response to variation or change in humidity of the atmosphere.

Another object is to provide a device which is of rugged but simple construction and which will be efficient in operation.

The invention consists in the improved construction and combination of parts, to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of this. specification, I have fully and rclearly illustrated two embodiments of my invention, in which drawing- Figure 1 is a top plan view of a control device .embodying my invention, but having a cover or casing member removed to show the internal construction;

. Fig. 2 is a view of the device in side elevation but with the cover or casing member in place and shown in longitudinal central section;

Fig. 3 is a detail View in section on the line 3-3 of Fig. 1;

Fig. 4 is a detail view in section on the line 4-4 of Fig. l, and

Fig. 5 is a top plan view of another form of control device embodying my invention, the cover or casing being removed. Y

Referring to the drawing by characters of reference, I designates a base or supporting member of insulating material, such as bakelite, for example. Adjacent one end of the member I there are laterally positioned and spaced supporting bosses or post members 2, 3. Mounted on the bosses 2, 3 there is a` supporting plate 4 which lies substantially parallel to the plane of the base member I and which is rigidly secured to the top faces of the lmembers 2, 3 by screws E, or the like. The plate 4 is prfovided with substantially parallel end slots 6 which provide therebetween a tongue portion 'I which is positioned between the members 2, 3. A U-shaped or horseshoe permanent magnet 8 is secure to the portion 1 which overlies the base of the magnet and is rigidly secured thereto by a rivet, or the like, 9. The

magnet 8 has its poles ID projecting upward through the end slots 6 with the top faces thereof lying substantially parallel to the plane of the base member I. The rivet, or the like, 9 also serves to secure a block member I I in position between the magnet poles, the block member extending from the magnet, as clearly indicated in LFig. 2, in the direction opposite to that of the tongue portion 'I.

Adjacent the other end of the base member I there is a supporting block I2, which is secured to the base memberI by screws, or the like, |22, and which `extends transversely of the base member. The supporting block I2 has an internally screw-threaded aperture I3 therethrough having 15 its longitudinal axis substantially parallel to the base member I and substantially in the longitudinal center line thereof, which is midway between the members 2, 3. An adjustment member I4, preferably a screw plug, see Fig. 4, is threaded into the bore or aperture I3. The member I4 is provided with a longitudinal recess I5 open at its end toward the magnet 8. Within the recess I5 there is a plimger memberl IB having a reduced end portion I'I, preferably in the form of a pin, which projects through an aperture in an annular stop member or Washer I8 secured in the open end of the recess I5. The member I8 seats against a shoulder I9 and is clamped thereagainst by turning over the end portion of the member I4, as at `30 2G, against the outer face of the member I8. The plunger I5 is normally urged toward the member IS by a coil spring, or the like, 2| positioned within the recess I5 and held under compression between the end or bottom wall of the recess and the plunger. The member I4 is preferably provided with an operating member 22, preferably a segmental plate, which is rigidly clamped and positioned on the member I4 by a binding screw, or the like, 23. Secured to the top face of the block I2 there are laterally positioned hinge members 26;, which are preferably of resilient sheet metal, preferably spaced equidistantly from the longitudinal center line of the base member I and extending toward the magnet 8. Each of the hinge members is provided with a clamping plate- 25 which extends slightly beyond the edge of the supporting block I2. The plates 25 are tightly clamped upon the top faces of the hinge members by screws, or the like, 26 which are threaded into the block I2 and which also serve to rigidly secure the members 24 in position. The free ends of the hinge members 24 are secured to the side edge portions of a lever or operating member 2I, which is preferably of sheet metal. The hinge 55 members 24 overlie the end edge portions of the member 21 and are clamped thereto by clamping plates 28 and rivets 29. The adjacent ends of the pairs of plates 25 and 28 are spaced slightly from each other so as to permit flexing of the members 24 and movement of the lever member 21 toward and from the base member I. The lever member 21 terminates at its free end in an armature portion 35 which overlies the magnet 8 within the magnetic influence of the poles I5. Adjacent the magnet 8, but between it and the supporting block i2, the lever member 21 is provided on its underface with a contact point or member 3l. The member 21 is preferably provided with a reduced neck-like portion 32 adjacent the contact member 3 I, which serves to render the armature portion exible relative to the body of the member 21. The member 21 is longitudinally slotted from its end adjacent the block I2 to a point adjacent the reduced portion 32, and the longitudinal edges of this slot 33 are provided with down-turned, substantially parallel, spaced anges 34. A moisture responsive element 35 is positioned within the slot 33 and has one end, which is preferably provided with an abutment member 35, seating against the inner end wall 31 of the slot 33, the end Wall 31 serving as an abutment. The element 35 is `of wood, preferably oak, and has the grain of the wood substantially at right angles to the length of the element. The wood element 35, which is substantially rectangu- 'lar, is provided with longitudinal grooves 38 in its side faces into which the flanges 34 extend. The element 35 is preferably provided with longitudinally extending recesses 39 in its top and bottom faces, which provide extended moisture receiving surfaces and which also serve to reduce the weight or" the element 35. The other end of the element 35 projects from the open end of the slot 33, as at 46, and is provided with an abutment member 4I which is engaged by the pin portion I1 of the plunger IB. The abutment members 35 and 4I are preferably flat metal plates having projections 42 which seat in apertures in the ends of the element 35 to hold the members 36 and 4I in position. The side edges of the member 21 have depending, substantially parallel, supporting arms 43 which are positioned opposite to each other and adjacent the hinge members 24. The arms 43 are joined by a cross member 44 .which is preferably substantially `.cylindrical and which has intermediate its ends,

and preferably midway therebetween, a circumferential groove 45 providing a substantially cylindrical reduced portion. Adjacent its end-s the member 44 is provided with circumferential grooves 46 which are received by slots 41 in the arms 43. The slotsv 41 preferably open from the side edge of the `arms 43 opposite to the supporting block I2, and are also preferably downwardly inclined. The `grooves 46 provide end head portions 48 on the member 44, which serve to retain the member 44 in position between the arms 43. The lever member 21 and the armature portion 35 are normally urged toward the magnet 8 by a spring 49, which is under tension, having one end provided with a loop or hook secured around the element 44 within the groove 45 so as to prevent lateral movement thereof, and having its other end, also provided with a loop or hook, secured to a post or stud member 5U fixed in the base member I. The block I2 is preferably recessed on its underside, as at 5I, to provide space for the end. of the spring 49 and the post 5U. The

nanges 34 are held in engagement with the lower edges of the slots 38 by a spring member 52 which.

is substantially rectangular in topplan, having side portions 53 which are provided with downward open recesses which seat on the element 44 adjacent the depending arms 43. The side portions 53 are inclined upwardly toward the block I2 and toward the magnet 8 on the opposite sides of the element 44, and are joined by cross members or portions 54 which bear Aagainst the under face of the element 35, so that the inherent resilience of the portions 53 act to urge the element 35 upward against the flanges 34. The post 50. which is preferably in the form of a bolt extending through an aperture in the base member I and clamped in position by a nut 55, also serves to rigidly 15x one end of a substantially L-shaped leaf spring 56 to the base member. The spring 56 has an upwardly extending arm 51 which is apertured to receive the end of the screw plug I4 and which bears against the adjustment member v22 to frictionally maintain it in adjusted position. The contact member 3| cooperates with a contact member 58 carried by a screw 55 adjustably threaded through theplate 4 and the member II. The contact member 58 is electrically connected to a terminal 59 by a lead wire 60 in contact with the plate 4 and scoured thereto by one of the screws 5. The contact 3| is electrically connected to a terminal 6I by a. lead wire 62 which is connected to one of the hinge member retaining screws 26, with the circuit being completed through the hinge 24 and lever member 21. A housing or casing 62a is preferably provided to enclose the operating mechanism and has an aperture 62b therethrough for projection of the member 22 through the casing, such that it may be manipulated from the outside of the casing. The side and end walls of the casing 62EL are preferably provided with elongated apertures 62c so that the element 35 will be responsive to atmosphere surrounding the casing 62a.

In the construction shown in Fig. 5, the lever member 21 is not provided with the depending flanges 34, and 'at the inner end of the slot has a bearing point 63. The lever 21 of Fig. 5 is also p-referably provided with side flanges 64 in lieu of the arms 43, which serve to lend rigidity to the intermediate portion of the lever member. These flanges 64 serve to support the cross member 44 as in the construction above-described and shown in Fig. 1. The spring is eliminated and in lieu thereof the block I2 is slotted, as at 55, in its top face into the bore I3 and the edges of the slot are drawn together by a screw 66 to frictionally resist turning movement o-f the screw plug I4. Positioned in the slot 33 of the lever member, there is a moisture responsive element 61, preferably of wood having the grain extending transversely to its length, which is substantially externally cylindrical and has a cylindrical bore longitudinally therethrough. The element 61 is provided with end caps 68 having reduced portions which t in the longitudinal bore, and having substantially conical, oppositely directed recesses 69 in their outer end faces. The projections 63 and I1 seat in the recesses 69 and serve to support the element 61 ln operative position. The remaining struc-ture of Fig. 5 is substantially identical with that of Fig. 1 above- AVdescribed and, therefore, the reference characened, as shown in Fig. 5, to reduce its weight and vary its sensitivity to the magnetic influence o-f the magnet 8.

'Ihe operation of the construction shown in Figs. 1 to 4 is as follows: The wood element 35, as shown in Fig. 2, has contracted, due to decreased moisture content in the atmosphere, suiciently to permit the spring 49 to pull the lever member 21 toward the base member I on its hinges 24 to thereby make contact between the members 3| and 58. As the relative humidity or the moisture content of the air or atmosphere increases, the moisture will be absorbed by the element 35, and due to the fact that the grain of the wood is transverse to its length, the element 35 will swell or expand longitudinally. As the expansive force of the element 35 increases, the combined opposing forces exerted by the attraction of the magnet for the armature portion 30 and of the sp-ring 49 acting through the arms 43 on the lever member 21 will be overcome. The attractive force of the magnet 8 is such that the contact between the members 3| and 58 will be broken with a quick and substantially snap action since the magnet 8 will hold the contact members in engagement until the expansive force of the wood element 35 has slightly bowed the lever member 21 in opposition to the force of spring 49. The armature portion 3D is preferably prevented by engagement between contact members 3| and 58 from contacting with theI magne-t poles ||l so that a slight air gap is maintained which renders the device very sensitive to movement of the portion 3l) relative to the poles I0. Adjustment of the plug |4 by the member 22 will regulate the range of operation of the device. M-ovement of the portion |1i toward the magnet 8 will decrease the extent to which the element 35 must expand and the force to be exerted thereby in order to overcome the spring 49 and the magnet 8 so that contact will be made and broken at a less relative humidity. It may be noted that variation in the air gap between the armature portion 30 and the magnet poles ||l will regulate the differential operation of the device, and that the air gap may be increased or decreased by adjustment of the screw 59. Increase in the air gap by decreasing the extent to which the lever moves in making contact will decrease the differential of operation, that is, will cause the contacts to be made and broken at a less difference in relativehumidity than when the air gap is small. The spring 2| serves as a safety means to take up overtravel of the element 35 on expansion.

The construction shown in Fig. 5 operates similarly to that above described, and it is believed the operation will be obvious from the foregoing description. The hollow wood element 61 renders the device of Fig. 5 more sensitive to variation in moisture content of air or atmosphere as it provides a relatively thin shell having a sulicient extended surface relative to its wall thickness to quickly take up or give off moisture from or to the atmosphere.

What I claim and desire to secure by Letters Patent of the United States is:

1. A device of the character described, comp-rising a base member, a support mounted adjacent one end of and on said base member, a lever member carried by said support and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said rst-named contact member', said lever member having an abutment, and a moisture responsive element positioned between said support and said abutment and operable upon variation of moisture conte-nt to move said lever member relative to said base member.

2. A device of the character described, comprising a base member, a sup-port mounted adjacent one end of and on said base member, a lever member carried by said support and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said iirstnamed contact member, said lever member having an abutment, a moisture responsive element positioned between said support and said abut- `ment and operable upon variation of moisture content to move said lever member relative to said base member, and means resisting movement of said lever member by said moisture responsive element.

3. A deviceof the character described, comprising a base member, a support mounted adjacent one end of and on said base member, a lever member carried by said sup-port and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said first-named contact member, said lever member having an abutment, and an elongated wood element positioned between said support and said abutment and operable upon change in dimension by Variation of moisture content to move .said lever member relative to said base member.

4. A device of the character described, comprising a base member, a support mounted on said base member, a lever member having a fulcrum comprising, resilient hinge means rigidly secured to said lever member and to said support, said lever member being movable relative to `said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said iirst-named contact member', said lever member having an abutment, and a moisture responsive element positi-oned between and engaging' said support and said abutment and operable upon absorption of moisture to ex said hinge means and move said lever member relative to said base member.

5. A device of the character described, comprising a base member, a. support mounted on said base member, a lever member carried by said support and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said rst-namcd contact member, said lever' member having an abutment, and a moisture responsive element extending longitudinally of said lever member, said element being positioned between and having its ends engaging said abutment and said lever member support whereby said element is operable upon absorption o-f moisture to move said lever member relative to said base member.

6. A device of the character described, comprising a base member; a support mounted adjacent one end of and on said base member, a lever member carried by said support and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said first-named contact member, said lever' member having an abutment, a moisture responsive element positioned between and engaging said abutment and said support and operable upon absorption of moisture to move said lever member relative to said base member, and a heli- .Iii

cal coil spring under tension having one end anchored and having its other end secured to said lever member and normally resisting movementl of said lever member by said element.

7. A device of the character described, comprising a base member, a support mounted on said `base member, a lever member carried by said support and movable relative to said base member, a Contact member carried by said base member, a contact member carried by said lever member and cooperable with said irst-named contact member, said lever member having an abutment, a moisture responsive element engaging said abutment and operable upon absorption of moisture to move said lever member relative to said base member, supporting members extending from the sides of said lever member toward said base member, a cross member joining said supporting members and carried thereby, and a spring having one end secured to said cross member and resisting moveme-nt of said lever member by said element.

8. A device of the character described, comprising a base member, a support mounted adjacent one end of and on said base member, a lever member carried by said support and movable relative to said base member, a contact member carried by said base member, a contact member carried by said lever member and cooperable with said iirst-named Contact member, said lever member having an armature, a magnet 'cooperable with said armature and carried by said base member, said lever member having an abutment, and a moisture responsive element positioned between and engaging said abutment and said support and operable upon absorption of moisture to move said lever member relative to said base member.

9. A device of the character described, comprising a base member, a support mounted on .said base member, a lever member carried b-y said support and movable relative to said base member, said lever member having a longitudinal slot open at one end adjacent said sup-port, a Contact member carried by said lever member adjacent the other end of saidr slot, a contact member carried Vby said base member and cooperable with said first-named contact member, and a substantially rigid moisture responsive element positioned in said slot and having one end engaging the end wall of said slot, the other end of said element engaging said support whereby expansion of said element upon abso-rption of moisture will move said lever member.

10. A device of the characte described, comprising a base member, a support mounted on said base member, a lever member carried by said support and movable relative to said base member, said lever member having a longitudinal slot open at one end adjacent said support, a contact member carried by said lever member adjacent the other end of said slot, a Contact member carried by said-base member and cooperable with said first-named contact member, a substantially rigid moisture responsive element positioned in said slot and having one end engaging the end Wall of said slot, and an adjustable abutment carried by said support, the other end of said element engaging said adjustable abutment whereby expansion of said element upon absorption of moisture will move said lever member.

11. A device of the character described, comprising a base member, a support mounted on said base member, a lever member having a longitudiml slot open at one end, resilient hinge members secured to said lever member at the sides of said slot adjacent the open end thereof, means securing said hinge members to said support, an abutment member carried by and projecting from said support, a substantially rigid moisture responsive element positioned in said slot and having one end engaging the end wall of said slot, the other end of said element engaging said abutment member, said element acting upon absorption of moisture to move said lever member, and means opposing movement of said lever member by said element.

12. A device of the character described, comprising a, base member, a lever member movably supported on said base member, said lever member having a longitudinal slot open at one end, ilanges on said lever member at the side edges of said slot, a moisture responsive element positioned in said slot and having one end engaging the end Wall of said slot, an abutment member engaging the other end of said element, said element having longitudinal recesses in its side faces receiving said flanges, and means opposing movement of said lever member by 'said element.

l13. A device of the character described, comy prising a base member, a lever member movably supported on said base member, said lever member having a longitudinal slot open at one end, flanges on said lever member at the side edges of said slot, a moisture responsive element positioned in said slot and having one end engaging the end wall of said slot, an abutment member engaging the other end of said element, said element having longitudinal recesses in its side faces receiving said iianges, means normally acting to maintain said flanges in engagement with the side edges of said recesses, and means opposing movement of said lever member by said element.

14. A device of the character described, comprising a base member, a lever member carried by said base member and having a longitudinal slot open at one end, a Contact member carried by said base member, a contact member carried by said lever member and cooperable with said rst-named contact member, a hollow Wood element positioned. in said slot and having one end engaging the end wall of said slot, and an abutment member carried by said base member and engaging the other end of said element whereby expansion of said element upon absorption of moisture will move said Contact members relative to each other.

l5. A device of the character described, comprising a base member, a lever member carried by said base member and having a longitudinal slot open .at one end, a Contact member carried by said base member, a contact member carried by said lever member and cooperable With said irst-named contact member, the end wall of said slot having a pointed abutment member, a pointed abutment member carried by said base member, .a hollow wood element positioned between Said abutment members, and end caps on said element having recesses receiving said abutment members.

16. A device of the character described, comprising a base member, a support mounted adjacent one end of and on said base member, a lever member carried by said support and movable relative to said base member, cooperable controlling elements carried by said base member and by said lever, said lever member having an abutment, and a moisture responsive element positioned between and engaging said abutment and said support and operable upon variation of moisture content to move said lever member relative to said base member whereby to move said cooperable elements relative to each other.

17. A device of the character described, comprising a base member, a support mounted on said base member, a lever member having a longitudinal slot open at one end, resilient hinge members secured to said lever member .at the sides of said slot adjacent the open end thereof, means securing said hinge members to said support, an abutment member carried by and projecting from said support, a substantially rigid moisture responsive element positioned in said slot and having one end engaging the end wall of said slot, the other end of said element engaging said abutment member, said element acting upon absorption of moisture to move said lever member, control means actuated by said lever member, and means opposing movement of said lever member by said element.

18. A device or the character described, comprising a base member, a support mounted on said base member, a lever member, a resilient sheet metal hinge member bridging a gap between and rigidly secured to said members to provide a fulcrum for said lever member, co

operable Contact members carried by said base member and said lever member, and moisture responsive means cooperable with said lever member and operable to move said lever member and one of said contact members relative to the other of said contact members,

19. A device of the character described, comprising a base member, a support mounted on said base member, a lever member movable toward and from said base member, a resilient sheet metal hinge member bridging a gap between and rigidly secured to said members to provide a fulcrum parallel to the plane of said base member for said lever member, cooperable contact members carried by said base member and said lever member, and moisture responsive means extending longitudinally of and cooperable with said lever member, said responsive means being operable upon variation of moisture content to move said lever member and one of said contact members relative to the other of said contact members.

20. A device of the character described, comprising a base member, a support mounted on said base member, a lever member carried by said support and movable relative to said base member, said lever member having an abutment facing said support, cooperable controlling elements carried by said base member .and by said lever member adjacent said support, a substantially rigid moisture responsive element having one end engaging said abutment, and an ad justable abutment member carried by said support, the other end of said element engaging said adjustable abutment member whereby expansion of said element upon absorption of moisture will move said lever member.

21. A device of the character described, comprising a base member, a support mounted adjacent one end of and on said base member, a lever member secured at one end to said support and movable relative to said base member, said lever member having an abutment facing said support, cooperable controlling elements carried by said base member and by the other end of said lever member, a substantially rigid moisture responsive element having one end engaging said abutment, and an adjustable abutment member adjustably screw-threaded through and carried by said support, the other end of said element engaging said adjustable abutment member whereby expansion of said element upon absorption of moisture will move said lever member.

22. A device of the character described, comprising a base member, asupport mounted on said base member, a lever member carried by said support and movable relative to said base member, said lever member having an abutment facing said support, cooperable controlling elements carried by said base member and by said lever member adjacent said support, .a substantially rigid moisture responsive element having one end engaging said abutment, an adjustable abutment member carried by said support, the other end of said element engaging said adjustable .abutment member whereby expansion of said element upon absorption of moisture will move said lever member, a cover member housing said lever member and said responsive element and having an opening, and an adjustment member carried by said abutment member and extending through said opening.

LEWIS W. EGGLESTON. 

